I wonder if Austin’s food trailer scene with its fixed locations and cable-spool seating would have taken such firm root if it were a guerrilla-style truck culture instead, leaving you to stand in the sun using your hands as Swiss Army fork, plate and table. Which one of these sloppy monsters do I tackle first with nowhere to sit except the car or back at the office? Yumé Burger’s a good test of that during its office stops on the weekdays, because this isn’t walk-around food. It’s certainly well-practiced food, being Eric Silverstein’s Japanese-influenced sister truck to his other enigmatic mobile operation called the Peached Tortilla. During the weekdays, it prowls progressive office parks, then moves downtown on the weekends to become part of the after-hours strolling carnival of the entertainment district.

The burger: The PoKu ($6, at top) is an avalanche waiting only for you to open the wrapper. Out tumbles excelsior ribbons of green and red cabbage in a fragrant conveyor sauce of wasabi and sesame, followed by razor-thin sweet-sour pickles that stay as cool as a CryoMax pack even in the direct sun. Twin blocks of pork belly slide out beside them, as big as dominoes for the hard-of-seeing, each with a tree-bark sear and alternating layers of flesh and fat exhaling anise like an incensed opium den-mother. All this happens on a bun as soft as a reliable promise without the saccharin insincerity.

Starting to sound like a long-winded haiku yet? It’s the hungry man’s answer to the effete pork belly slider, and the flavors all pointed in the same direction: East. And that’s good. But this burger, just like the next, was anchored by a thick beef patty that had barely been cooked. Not seared to a rosy medium-rare, but barely transformed from the warm pink of raw ground beef beneath a cloak of light brown only a few millimeters thick. It tasted fine, but that color is a gambler’s blush.

PoKu’s cousin the JapaJam ($6, at left) drew its Rising Sun profile from a tomato jam you can picture by imagining sweet chile sauce from a jelly jar. The menu board shows the beef resting on the jam as if it were a waterbed, bulging at the sides in its corpulent bounty. My burger had more like a weak schmear of tomato jam, and the hot mess of the burger swamped it with fried egg and its flowing golden core, strings of fried onion, pepper-jack cheese and a Japanese barbecue sauce like a fender-bender at the corner of Sorghum and Sriracha. Cook the beef more thoroughly and this would be a monster — make that a dragon — of a burger.

The extras: Here’s where the haiku starts abandoning its syllable count. A $2.75 boat of fries illustrated how hard it is to get hand-cut potatoes right. Your good intentions can give you a crisp union of skin and starch and oil or a waxy stack of semi-translucent potato noodles. This time I got the second one, and no sprinkle of sesame and salt nor 50-cent thimble of barbecue sauce could save them. Sweet potato fries ($3.50), on the other hand, came crisp and sweet, accelerated by that same sesame salt and another 50-cent dipping sauce of wasabi mayo. The sweet potato fries come frozen, which reinforces my notion that sometimes you’ve just got to go with what works instead of what sounds proper to the snob squad.

The drinks: One of my favorite parts about this kind of food truck is the pirate’s chest of drinks in crushed ice under the fold-up flaps. A half-liter green bottle of Mexican Coke is $3, and a tallboy can of SweetLeaf tea is $2. Peach, of course, to honor Yumé’s Peached Tortilla ancestor.